#include<stdio.h>
#include<string.h>

void fun(char a[],char b[])
{
	int sign,key=0,len=strlen(a);
	for(sign=0;sign<len;sign+=2)
	{
		b[key++]=a[sign];
	}
}
int main()
{
	char a[100]={'\0'},b[100]={'\0'};
	gets(a);
	fun(a,b);
	puts(b);
	return 0;
}
